BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Memento EPFL//
BEGIN:VEVENT
SUMMARY:The latest from flexLab: Mechanics of Slender Structures and Fluid
 -Structure Interactions
DTSTART:20180524T161500
DTEND:20180524T171500
DTSTAMP:20260505T025323Z
UID:f363288ba00f7982cdb712dfdba8cafdf28ee45e642bc0c17477f0c8
CATEGORIES:Conferences - Seminars
DESCRIPTION:Matteo Pezzulla\, Dong Yan and Paul Grandgeorge - EPFL STI
  IGM Flexible Structures Laboratory (flexLab)\nAbstract\nDeformation of 
 perforated elastic sheets due to the hydrodynamic loading by a viscous flu
 id\, by Matteo Pezzulla\nFrom spider webs and insect wings\, to wire fen
 ces and parachutes\, Nature and technology provide us with vast examples o
 f perforated flexible structures that undergo elastic deformation due to f
 luid flow. Whereas fluid flow through porous media has been studied extens
 ively\, the fluid-structure interactions of a perforated slender elastic o
 bject that undergoes large deformations due to the loading of a surroundin
 g viscous fluid has received much less attention. I will talk about our on
 going research\, where we use precision desktop experiments to focus on th
 e prototypical problem of a perforated elastic plate moving through a visc
 ous fluid\, at low to moderate Reynolds number. Via a reduced theoretical 
 model based on Kirchhoff-Euler beam theory coupled with a low Reynolds des
 cription for the fluid forcing\, we seek to provide a predictive framework
  for the deformation of perforated plates due to hydrodynamic loading. We 
 hope that our findings may lead to a better understanding of fluid-structu
 re interactions between porous slender structures and viscous flows\, acro
 ss biological and technological applications.\n\nDefect-controlled bucklin
 g of depressurized elastic spherical shells\, by Dong Yan\nSpherical shell
 s are ubiquitous in nature and engineering structures\, across a wide rang
 e of length-scales. Small geometric imperfections can substantially decrea
 se the buckling strength of shells. In this talk\, I will present our ongo
 ing research on the buckling of spherical shells containing a thickness de
 fect. Through a customizable coating technique\, a thickness defect with c
 ontrollable geometric properties is fabricated by blowing the polymer laye
 r during curing. We vary the amplitude of thickness variation and study t
 he buckling behavior of our spherical shells. We quantify the effect of a 
 thickness defect on the buckling strength. The experimental results are th
 en contrasted against finite element modeling (FEM) simulations. Upon vali
 dation of the numerics\, we then use FEM to perform a broader exploration 
 of the parameter space. Our results lead to a better understanding of impe
 rfection sensitivity\, which is a concrete foundation for accurately predi
 cting the buckling pressure of shell structures in engineering.\n\nUnravel
 ling the tight interplay between geometry and mechanical response of elast
 ic knots\, by Paul Grandgeorge\nMay they be functional for shoelaces\, u
 ndesirable when tangling up cables\, or even aesthetically appealing in Ce
 ltic decoration art\, knots are dealt with on a daily basis. Even for medi
 cal purposes\, surgeons have employed knots to secure sutures for millenni
 a. Even though they come across in such a wide variety of fields\, the pre
 dictive understanding of knot topology and mechanics remains challenging. 
 Past studies have primarily focused on mathematically ideal knots\, discar
 ding most physical properties of the knotted rod such as cross-section dia
 meter\, bending stiffness or frictional behavior along self-contact region
 s. In this talk\, I will present our ongoing experimental research on elas
 tic knots\, performed in collaboration with Prof. John Maddocks. In partic
 ular\, I will focus on the orthogonal clasp\, a simple yet rich configurat
 ion (2 fibers crossing\, see picture)\, to present our 3D-imaging and imag
 e-processing strategy. We hope the gained physical insight will pave the r
 oad for future material and configuration optimizations of functional knot
 s in the areas of surgery and other engineering applications.\n\nBio\nMatt
 eo Pezzulla is a postdoc in the Flexible Structures Laboratory (flexLab
 ) at EPFL. He is interested in the fluid-structure interactions (FSI) of p
 erforated slender structures and viscous fluids\, at low Reynolds numbers\
 , and in the geometric mechanics of slender structures such as shells\, po
 ssibly coupled with swelling.\nDong Yan is a postdoc in the Flexible Stru
 ctures Laboratory (flexLab) at EPFL. He is interested in the mechanics of
  slender structures. He is currently working on the buckling of spherical 
 shells.\nPaul Grandgeorge is a postdoc in the Flexible Structures Labora
 tory (flexLab) at EPFL. He is interested in the mechanical behavior of s
 lender structures undergoing non-linear deformations. More specifically\, 
 he is currently working on the mechanics of elastic knots.
LOCATION:MED 0 1418 https://plan.epfl.ch/?room==MED%200%201418
STATUS:CONFIRMED
END:VEVENT
END:VCALENDAR